Refining petroleum oils



Dec. 18, 1945. A. PQHEWLETT ETAL 2,391,091

REFINING PETROLEUM OILS Filed Dec. 20, 1939 CL H Y TRfHT/NG DIST/L l 3770M ment in the desulfurization Patented Dec. 18, 1 9 45 s PATEN asrmmc Parson-ion OILS Amiot r. Hewlett, Summit, and Gerald E. rhulips, Cranford, N. 1., assignors to'Standai-d Oil Development Company, a corporation of Delaware Application December 20, 1939, Serial No. 310,094

v 7 Claims.. (cr es-2s) The present invention relates to the refining of petroleum oils. The invention is particularly concerned with the treatment of virgin petroleum oils, which oils have not been subjected to temperature a d pressure conditions adapted to producc cracking, with bauxite under non-cracking conditions. In accordance with the present process. virgin petroleum oils are contacted with bauxite under non-cracking conditions at a'temperature in the range of about 780 F. to about 7 It, is. well known in the art to treat petroleum oils with various metallic oxides and the like in various refining operations. For example, it is known to remove objectionable sulfur compounds from petroleum oils, particularly from petroleum oils boiling in the motor fuel boiling range, by contacting the same with bauxite at peratures which vary over a relatively wide range. However, temperatures employed 'in.thetreatment of virgin oils in commercial operations are elevated temin theiran'ge from'about 600? F. to 700 F., even thou'sh broad statements have been made that temperatures'as high as 800 F. may be employed in the bauxite treatment of petroleum oils. Temperatures above '750-F. are not employed in desuliurization of virgin petroleum oils when utilizing bauxite and,-as a matter of fact, a practice is to'employ temperatures in the range from about 775 F."to'85 0 IE. to regenerate the bauxite. The

utilization of temperatures in the range below about 750 'F. in desulfurization operations employing' bauxite when processing virgin oils was based upon the fact that no substantial improve- I operation is secured byemploying temperatures above this range which we have found to be substantially correct. However, we have discovered that if virgin petroleum oils are treated'by contacting the same in the vapor phase withbauxiteunder non-cracking conditions at temperatures above about 780 F., particularly above about 800 E, unexpected 'deslrable benefits aresecured. Although' the extent oi the-desulturizationis not materially increased by utilizing temperatures (above about 650 F. to

750 1",, the bauxite at temperatures above these ranges-apparently functions to rearrange the molecular structure of the molecules in a manner whichimproves the clear octane number of the treated product, as well as the ability of the point prime cut naphtha, is introduced into bauxite treating plant I by meansof feed line 2.

' Prior to introducing the oil into bauxite treating plant I the temperature of the same may be raised to thedesired extent by means of heating unit 3.- The bauxite contacted oil is withdrawn from bauxite treating plant I" by means of line 4, passed through cooler 5,,and introduced. into clay contacting plant 6. The bauxite and clay treated oil is withdrawn'from-clay contacting plant 6 by,

means ofline l, cooled in cooler 8, and introduced into distillation plant 8. Uncondensed gases are removed overhead fromdistillation plant 9 by means of' line In, while the bauxite and clay treated material is withdrawn by means of line I I and handled in any manner desirable. Under certain? conditions the bauxite treated oil may bypass clay contacting plant 6 by means'of line l2- and be introduced directly into distillation unit 9. Portionsof the gas removed overhead from distillation unit 9 in the preferred modification of the invention are recycled and'introduced into the fresh feed by means of line l2. These recycled gases may be raised to the desired temperature by passing the same through heating unit. lit Gases may be withdrawn from the system b meansoflinell. u The process of the present invention may vary widely. Any virgin feed oil maybe employed which will not decompose into relatively higher and into relatively lower boiling fractions at these temperatures. The process, however, isparticularly applicable in the treatment of prime cut. petroleum oils boiling in the motor fuel boiling range. In general, the conditions: are adapted in the bauxite treating plant so that substantially non-cracking conditions exist. It is essential that the temperatures employed be above about manner. It has been found that overall optimum results are secured when the temperature maintained in the bauxite treating unit is in the range from 800 F. to 820 F. Under the conditions of operation substantially no gas is formed. However, the small amount of gas removed from distillation unit 9 by means of line I comprises from 50% to 85% hydrogen by volume, based on dry gas. By recirculating the total quantity of this gas, we have found that the catalyst life is materially lengthened and that improved yields are secured.

In order to further illustrate the invention, the following examples are given which should not be construed as limiting the same in any manner whatsoever: 7

EXAMPLE 1 Prime cut light petroleum oils secured from a West Texas crude oil boiling in the motor iuel boiling range were bauxite treated at various temperatures with the following results:

Table 1 The volatility of the respective oils as determined by an Engler distillation was as follows:

Table 2 Treated oils Feieid 1 Opera- 0 ra- 0 a- Operation A ti i i B a o tion D 1mm! boiling point. 100 a. o 9 95.0 96.0 102 Percent distilled at- 158 F 10. 0 11. 6 11. 0 11. 0 11. 5 39. 0 40. 5 39. 6 40. 0 41. 0 72. 0 72. 0 73. 0 72. 0 72. 6 302 F 89. 5 90. 5 91.0 91.0 90. 0 Final boiling point 365 367 365 367 381 Percent recovered 98. 0 98. 0 99. 0 98. 6 98. 6 Percent loss 1. 0 1. 1 0. 3 0. 6 0. 7 Gravity 62. 3 62. 7 62. 7 02. 5 61. 8

zone at which cracking or decomposition oi the oil occurs.

Exmru: 2

Additional prime cut heavy petroleum oils secured from a West Texas crude oil boiling in the motor fuel boiling range were bauxite treated at various temperatures with the following resuits:

Table 3 Clear octane The volatility of the respective oils as determined by an Engler distillation was as follows:

Table 4 Treated oil: at

Operr 0 0 tionA tsi't e858 .95;

Initial boilin point---" 234 $0 228 228 Percent dis dat- From the above data it is apparent that a molecular arrangement occurred, particularly with respect to the fractions bauxite treated above about 780 F.

From the above data it is apparent that although the reduction in suliur was not substantially increased by temperatures above about 650 F. to 750 F., the quality of the product was substantially improved by an apparent molecular rearrangement and that this arrangement occurs to the maximum extent under non-cracking conditions at a temperature of above about 800 F.

What we claim as new and wish to protect by Letters Patent is:

1. Process for the treatment of prime cut petroleum oils comprising contacting said petroleum oils with a catalyst consisting oi baunte in the vapor phase at a temperature in the range from about 780 F. to 850 F. whereby substantially no cracking of the oil occurs and substantially no gas is formed.

2. Process for the treatment of prime cut petroleum oils boiling in the motor iuel, boiling range containing objectionable sulfur compounds, comprising contacting said petroleum oils in the vapor phase with a catalyst consisting of bauxite at a temperature in therange from about 780 to 850 F., whereby said objectionable sulfur compounds are removed and a molecular rearrangement or the molecules of said petroleum oil is secured with substantially no cracking or the oil occurring and with less than 1% of gas being formed.

8. Process in accordance with claim 2 in which said petroleum oil is contacted with bauxite at a tezmperature in the range from about 800 F. to 8 0 F.

4. Process for the refining of prime cut petroleum oils comprising contacting said petroleum oils with a catalyst consisting of bauxite under non-cracking conditions at a temperature in the range from about 780 F. to 850 F., whereby substantially no gas is formed, withdrawing said bauxite treated oil and introducing the same into a distillation unit in which gases comprising substantially hydrogen are removed from the bauxite prising contacting said petroleum oils with a catalyst consisting of bauxite under substantially non-cracking conditions at a temperature in the range fromabout 780 F. to 850 F., whereby less than 1% or gas is formed, clay treating said bauxite treated oil and removing therefrom uncondensed gases, recycling said gases to the fresh feed being bauxite treated.

'1. Process in accordance with claim 6 in which the temperature of the petroleum oils is in the range from about 800 F. to 820 F.

AMIOT P. HEWLETT. GERALD E. PHILLIPS. 

